Jakob schmid and johannes mohler



UNITED STATES PAT NT OFFICE.

JAKOB SCHMID AND J OHANNES MOHLER, OF BASLE, SWITZERLAND, ASSIGNORS TOTHE SOCIETY OF CHEMICAL INDUSTRY IN BASLE,

OF SAME PLACE.

' BLUE DYE.

SPECIFICATION forming part of Letters Patent No. 538,183, dated April23, 1895.

Application filed August 4, 1894. Serial No. 519.486 ($peoimens.)

T0 aZZ whom it may concern:

Be it known that we, JAKoB SCHMID and J OHANNES MOHLER, citizens ofSwitzerland, residing at Baslefiwitzerland, have invented newand usefulImprovements in the Production of a Blue Coloring-Matter or Dye-Stud, ofwhich the following is a specification.

Our invention relates to the manufacture of a new and valuable poly oxythionin coloring matter resulting by condensation of 7. oxy 1.2naphthoquinone 4. monosulfonic acid with thiosulfonic acid of para amidomethyl (or ethyl) benzylanilin sulfonate of soda.

For the production of the said 7. oxy 1.2 naphthoquinone 4. monosulfonicacid, mononitroso-dioxy-naphthalene 2.7 is dissolved in a coldsolution'of bisulfite of sodium and treated with concentrated muriatic acid. Bysimultaneous reduction and sulfonation, a. difficultly soluble (1.)amido (2.7) dioxy naphthalene (4.) sulfonic acid is formed, which byfurther treatment with oxidizing agents, especially with nitric acid, isconverted into the new 7. oxy 1.2 naphthoqui'none 4. sulfonic acid. Thislatter is separated from the solution in the form of its potassium saltcrystallizing in red brown needles or leaves and it is represented bythe formula Hereinafter we give an exact description of the manner inwhich our invention is to be carried out into practice.

One hundred and seven kilos of a solution containing twenty-eight percent. of methyl benzyl anilin sulfonate of soda are converted into thenitroso derivative in the usual way by the action of 21. kilos ofmuriatic acid of 21 Baum and seven kilos of sodium nitrite. The mass isleft to stand during twelve hours.

In order to efiect the conversion into the thio sulfonic acid,thirty-five kilos of acetic acid (containing forty per cent. of pureacid) and a solution of fifty kilos of sodium thiosulfate-are added andthe temperature is raised to from to centigrade until the nitrosocompound has disappeared. To the thus produced thiosulfonic acid of paraamido methyl benzylanilin mono sulfonate of soda, a concentratedsolution of thirty kilos of 7. oxy 1.2 naphthoquinoue 4. mono sulfonateof potassium is added and the mass is heated from two to three hours.From the dark colored liquid, the new dyestuff separates out as a greencrystalline powder of metallic luster. It is washed in cold water anddried when it assumes a dark violet color.

The new coloring matter corresponding to the formula (where R signifiesmethyl or ethyl) forms a changing to brown and green-blue underseparation of blue-violet flakes upon addition of water. In hot water orin a dilute ammonia solution, the new dyestuff dissolves with ablue-violet color. I

The new coloring matter is difticultly soluble in hot alcohol andinsoluble in ether and benzene. It dyes on wool mordanted with chromiumsalts blue shades of great fastness to washing and light.

What We claim as new, and desire to secure by Letters Patent, is-

l. The process for the production of a new poly oxythionin coloringmatter by condensation of 7. oxy-1.2 naphthoquinone 4. monosulfonic acidwith thiosulfonic acid .of para amido alkyl benzylanilin sulfonate ofsoda.

2. As a new article of manufacture the poly-oxythionin coloring matterwhich can be obtained by condensation of 7. oxy 1.2 naphthoquinone 4:.monosulfonic acid with thiosulfonic acid of para amido alkyl benzylanilin sulfonate of soda, corresponding to the formula- 1o (whereRsignifies methyl or ethyl) forming a dark violet powder which dissolveswith a blue-violet coloration in concentrated sulfuric acid, changing tobrown and green-blue unwitnesses.

" JAKOB SOHMID.

J OI-IANNES MOHLER. Witnesses:

GEORGE GIFFoRD, G. A. BURCKHARD.

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